The Dome

pier construction

The main part of my observatory is of course the telescope itself.To have a sturdy mount not sensitive to vibrations is essential, so how did I solve this problem?First at the place were I should have my dome I dug a hole in the ground 60 cm deep.In this hole I put a flagpole base mount and filled the hole with concrete.It is a very good idea to do it this way because the flagpole mount allows you to adjust the pole if the ground sets after winter.Then I went to a company that makes flagpoles called Formenta, here were I live and for less than 20 $ bought the bottom part of a flagpole (this is the part that is casted into the flagpole during construction, it is of galvanised metal and therefore it is not only sturdy but also it doesn’t rust) This part has tree adjusting holes to fit the adaptor in the ground.When this was finished I turned to the mounting of the scope itself.As I am on a low budget I opted to use an old mead star finder mount that was lying around and together with one aluminium adaptor ring turned in my lathe it fitted perfect.I then filled the tube with concrete to make it even sturdier.So much for the pier, but then I realised a problem after having constructed the base I found that air venturing in under the floor was compressed by the shape of the floor itself (it looks like a bit of a cake) this fact pressed the air up inside the dome with tremendous force even after the insulation plate was mounted making the mount wet of incoming moisture.I therefore removed the insulation plate and the pier ( by now really heavy) and took a piece of butyl rubber canvas, for making ponds and made tree small holes for the flagpole bolts , repositioned the pier and stapled the canvas on the underside of the floor thereby stopping all draft and subsequently no more moisture.